﻿using System;

class Teste
{
    static void Troca(ref string s, ref string t)
    {
        string tmp = s; s = t; t = tmp;
    }
    static void Main()
    {
        string a = "Passo", b = "Coelho";
        Console.WriteLine(a + b);
        Troca(ref a, ref b);
        Console.WriteLine(a + b);
        Console.ReadLine();
    }
}
